Multigenerational Risk for Autism

Natasha Marrus, MD, PhD and Daniel Gray, MSW
Washington University in St. Louis

Alison Marvin, PhD
Interactive Autism Network

Date Published:

November 11, 2016

An Army of Grandmas Help IAN Learn more about Autism

An important question for many parents of children with autism involves the risk of autism in later generations. Natasha Marrus, MD, PhD, a child psychiatrist and researcher at Washington University in St. Louis, has also been interested in this issue, particularly for children of sisters who have a brother with autism, but no diagnosis of autism themselves. As females, these sisters are at lower risk of autism spectrum disorder (ASD), which is much more common in males, but what about their children? To answer this question, Dr. Marrus proposed collecting behavioral data from 500 families with a history of ASD. With the support of a post-doctoral fellowship award from the Autism Science Foundation, she and her mentor, Dr. John N. Constantino, turned to the Interactive Autism Network (IAN) to be a research partner in developing an online platform for collecting data from the uniquely large number of families in IAN Research.

The Mothers and Grandmothers 2B (MGM-2B) pilot project launched in January 2016. Mothers of a child with ASD and who were also grandmothers or expecting grandchildren completed online questionnaires about their family history and the social behavior of their grandchildren.

The study’s research centered on the female protective effect, through which females are biologically protected from developing ASD. This is in keeping with the much higher prevalence of ASD in males than in females. One of the goals of the study was to determine whether unaffected female siblings of a brother with ASD carry silent genetic risk for ASD that could be passed to their own children. Preliminary data from a small group of participants suggest that male children of these female siblings are at a much greater risk of ASD than males in the general population.

Initial results from this study were presented at the Autism Science Foundation (ASF) Day of Learning 2016 by Dr. Constantino. Watch a video of his talk “Determining Risk for Autism in Children of Siblings.” To go directly to a discussion of this project, which involves "an army of grandmas," skip to 13:16 minutes into this 20-minute presentation.

While these initial findings are not conclusive, they have motivated the study team to continue to investigate the female protective effect and related questions about transmission of risk for ASD in subsequent generations of family members. In January 2017, qualified mothers who are IAN Research participants should look for an IAN 60-Second Survey to assess potential interest in participation for a future expanded IAN multi-generational family study of ASD.

If you have questions about this research, please contact the Washington University MGM-2B team at 314-362-3734.

Research note: Families and individuals with autism spectrum disorder play a critical role in helping researchers and clinicians better understand the disorder. Find out how you can participate in Interactive Autism Network (IAN) Research in a secure, online setting. By participating, you can help make new discoveries and empower advocates to improve the lives of children and adults with ASD.